1. CATEGORY OF INVENTION
This invention is concerned with a hand exerciser for strengthening the hand of a human being.
2. DESCRIPTION OF THE PRIOR ART
Various articles of manufacture have been conceived to exercise the hand and give to the user strength of the fingers and the thumb as well as to stimulate the muscles and the blood flow in the hand and and the development of the forearm. Reference is made to the following patents which attempt to solve this problem.
U.S. Pat. No. 4,226,412 discloses a double handle mounted on two U-shape mounted members wherein there are tension springs extending laterally between the U-shaped members. PA1 U.S. Pat. No. 1,620,910 discloses a plurality of springs mounted laterally on two parallel members with two handles whereby the inside handle pulls against the tension of the springs toward the fixed handle. PA1 U.S. Pat. No. 689,652 discloses two parallel members with two cross members whereby a plurality of springs are maintained against the cross members. Attached to the structure of the device containing the springs is an inside handle. The inside handle is then pulled toward the outside handle against the tensions of the springs. PA1 U.S. Pat. No. 668,473 discloses a system whereby there is a U-shaped member mounted on two vertical members against a door or a wall. There is a spring mounted on the mounting member with a handle mounted on a shaft containing the spring. The spring on the inside controls the inside handle. The user places his hand on the outside handle and pulls the inside handle against the tension of the unitary spring towards himself.
The above prior art does not disclose the details of structure on the unitary shaft with bushings and separators that prevent buckling of the spring or twisting thereof.